Merck recently announced the publication of the results of a post hoc analysis of the Phase III CLARITY study in Multiple Sclerosis Journal. The analysis showed that Cladribine Tablets reduced the annualised rate of brain volume loss – also known as brain atrophy – compared with placebo in patients with relapsing remitting multiple sclerosis (RRMS).
In addition, the analysis found that patients with lower rates of brain atrophy showed the highest probability of remaining free from disability progression at two years. This supports existing findings that increased brain volume loss over time is associated with worse clinical outcomes, such as increased disability progression and cognitive changes, in patients with multiple sclerosis.
“Evidence shows that brain atrophy in general accumulates throughout the course of multiple sclerosis and is associated with disability progression. This analysis is important because it confirms the link between reduced brain atrophy and reduced disability progression found in the CLARITY study,” said Nicola De Stefano, lead author of the publication and Associate Professor of Neurology, Department of Medicine, Surgery and Neuroscience, University of Siena.
The CLARITY study was a two-year (96-week), randomised, double-blind, placebo-controlled Phase III study of Cladribine Tablets in 1,326 people with RRMS. The CLARITY study primary (rate of relapse at 96 weeks) and key secondary endpoints (proportion of patients who were relapse free and the time to sustained progression of disability) were met. These outcomes and safety results were published in The New England Journal of Medicine.
The brain atrophy analysis evaluated the effect of Cladribine tablets on brain volume loss (BVL) over 2 years in RMS and the association of BVL with confirmed disability progression in 1,025 (77.3%) of the patients in CLARITY. The mean percentage brain volume loss per year was significantly reduced in patients treated with Cladribine Tablets 3.5 mg/kg (–0.56%±0.68, p=0.010, n=336) and 5.25 mg/kg (–0.57%±0.72, p=0.019, n=351) compared with patients treated with placebo (–0.70%±0.79, n=338). The risk of disability progression was also significantly lower in patients treated with Cladribine Tablets 3.5 mg/kg (HR 0.63, 95% CI 0.438, 0.894; p=0.010) and 5.25 mg/kg (HR 0.58, 95% CI 0.406, 0.833; p=0.003) than in those treated with placebo. After adjusting for treatment group, percentage brain volume loss per year showed a significant correlation with the cumulative probability of disability progression in the overall study population (HR 0.67, 95% CI 0.571, 0.787; p<0.0001).
“These findings reinforce and expand on the consistent and positive effect of Cladribine Tablets in improving clinically relevant outcomes, such as reducing relapse rate and disability, and further our resolve to make this investigational therapy available for patients living with RRMS,” said Steven Hildemann, MD, PhD, Global Chief Medical Officer and Head of Global Medical Affairs and Safety, Merck.
CLARITY study design
The CLARITY study was a two-year (96-week), randomised, double-blind, placebo-controlled, international study. It randomised 1,326 patients with relapsing remitting MS according to the revised McDonald criteria. Study participants were randomised to one of three different treatment groups consisting of two different dose regimens of Cladribine Tablets or matching placebo tablets (1:1:1 ratio).
The primary endpoint of the CLARITY study was the relapse rate over 96 weeks. Secondary endpoints included MRI endpoints, proportion of subjects relapse-free and disability progression at 96 weeks.
Lymphopenia was the most commonly reported adverse event (AE) in patients treated with Cladribine Tablets. The incidence of infections was 48.3% with Cladribine Tablets and 42.5% with placebo, with 99.1% and 99.0% rated mild-to-moderate by investigators.
About Cladribine Tablets
Cladribine Tablets is an investigational short-course oral therapy that selectively and periodically targets lymphocytes thought to be integral to the pathological process of MS. Cladribine Tablets is currently under clinical investigation and not yet approved for the treatment for any use in the United States, Canada and Europe. In July 2016, the European Medicines Agency [EMA] accepted for review the Marketing Authorisation Application (MAA) of Cladribine Tablets for the treatment of relapsing remitting multiple sclerosis